The present invention relates to a method and a device for measuring the angle of rotation of the steering shaft of a motor vehicle and, more particularly, to a method and a device designed to be used with an angular position sensor which emits a signal representing the relative position of the steering shaft for only one turn.
In certain modern motor vehicles, an angular position sensor sends a signal representing the angle of rotation of the steering shaft, or of the steering wheel, of the vehicle to an electronic computer which is part of a device for controlling an adaptable suspension, for example. The angle of rotation of this shaft determines the steering angle of the wheels and, consequently, the resulting lateral acceleration of the vehicle. The suspension of the vehicle is corrected according to the result of the calculation of the lateral acceleration.
In order to measure the angle of rotation of the steering shaft, use is commonly made of a potentiometric sensor coupled mechanically to this shaft by a gear train ensuring reduction of the rotation of the shaft. This gear train adapts the total angular travel of the steering shaft (equal to several turns) to that of the wiper of the potentiometric sensor (equal to one turn only). The presence of this gear train adversely affects the cost of such a sensor.